Quality documents for machined parts are the records that show a delivered part matches its order: a material certificate (usually EN 10204 type 3.1), a certificate of conformity, a measurement report, a first article inspection (FAI) report and, for automotive parts, a PPAP or VDA 2 approval package. Each answers a different question: the material certificate says what the part is made of, the measurement and FAI reports say what was measured, and the PPAP package says whether the process can repeat it.
Which quality documents come with machined parts?
An order that says "with certificates" does not say which. The documents below are not interchangeable, and a missing one usually surfaces at incoming inspection, after the parts have crossed a border.
Table 1. Quality documents for machined parts: what each proves, who issues it, when it is called for
| Document | What it proves | Issued by | Called for when |
|---|---|---|---|
| EN 10204 type 3.1 certificate | The material conforms to the order, with test results (chemistry, mechanical properties) for the delivered batch | Mill, foundry or heat treater; validated by its inspection representative independent of production | The drawing or order requires material traceability |
| Certificate of conformity (CoC) | The supplier declares that the delivery matches the order and drawing | Machining supplier | The order lists it, usually with every delivery |
| Measurement report | Measured values of named characteristics against the drawing | Machining supplier | A drawing note, control plan or order fixes the characteristics and the sample size |
| FAI report (AS9102 format) | The first part meets every drawing characteristic, and materials and special processes are recorded | Machining supplier | First production run, design change, or a change of source or process |
| PPAP package (AIAG) | The production process can make conforming parts; 18 elements plus a part submission warrant | Supplier, to the automotive customer | The customer requires approval before series delivery |
| PPA package (VDA 2) | The same question under the German procedure, with scope agreed per product | Supplier, to the automotive customer | The customer works to VDA 2 |
Source: EN 10204:2004; SAE AS9102C:2023; AIAG PPAP, 4th edition; VDA Volume 2, 7th edition (January 2026).
The management-system certificate of the supplier (ISO 9001, IATF 16949, AS9100) is a different thing. It describes the supplier, not the delivery. See which supplier certificate matters for your part.
What does an EN 10204 3.1 certificate prove?
EN 10204:2004, "Metallic products, Types of inspection documents", defines four document types for the delivery of metallic products such as plates, bars, forgings and castings. The 2004 edition, published 2004-10-20, is the current one as of 2026-10-30.
Table 2. Inspection document types in EN 10204:2004
| Type | Name | Content | Validated by |
|---|---|---|---|
| 2.1 | Declaration of compliance with the order | Product complies with the order; no test results | Manufacturer |
| 2.2 | Test report | Compliance, plus results of non-specific inspection | Manufacturer |
| 3.1 | Inspection certificate 3.1 | Compliance, plus results of specific inspection of the delivered product | Manufacturer's authorised inspection representative, independent of the manufacturing department |
| 3.2 | Inspection certificate 3.2 | As 3.1 | The manufacturer's independent representative and either the purchaser's authorised representative or an inspector designated by official regulations |
Source: EN 10204:2004, as summarised by Wermac and LRQA.
Specific inspection means tests on the products supplied or on a test unit from which they come. A 2.2 report rests on non-specific inspection, tests the manufacturer runs on its regular production, so it does not give values for your batch.
Three limits matter for machined parts.
First, the certificate describes the material, not the part. It does not say whether a bore is within tolerance or whether a heat treatment was applied after machining unless the order made that a tested requirement. Dimensions belong in a measurement or FAI report.
Second, the issuer is the party whose operations set the material properties. LRQA's guide to the standard describes a stockist that only saws, drills, grinds or turns material as not having manufactured it. A machine shop therefore forwards the 3.1 of the mill or foundry and ties it to each part by heat or batch number. A drawing that asks the machine shop for "3.1 on the finished part" needs a clarification of what is to be tested and by whom.
Third, older drawings may cite types from the 1991 edition. The 2004 edition kept 2.1, 2.2, 3.1 and 3.2 and dropped 2.3 and 3.1.A, 3.1.B and 3.1.C. LRQA notes that the certificate with independent third-party involvement carried the number 3.1 in 1991 and is type 3.2 since 2004. Ask which one the buyer means.
EN 10168:2004 lists the information that an inspection document for iron and steel products may contain, with a section code for each item, so that a 3.1 certificate from one mill reads like another. It is also current as of 2026-10-30. The EN 10204 guide goes through the four types in more detail.
What is the difference between a CoC and a measurement report?
A certificate of conformity is the supplier's statement that the delivery meets the order. ISO/IEC 17050-1:2004 sets general requirements for a supplier's declaration of conformity in any sector, but no standard fixes the layout of a CoC for a machined part. Typical content is the part number and revision, the order number, the quantity, the conformity statement, the date and a signature. A CoC is only as strong as the evidence behind it. It contains no measured values unless the order asks for them.
A measurement report is the evidence. It lists the characteristics that were measured, the values found, the measuring equipment and the number of parts measured. The drawing, a control plan or the order sets which characteristics are reported and how many parts are sampled. Without that agreement, "with measurement report" can mean one part or all of them. Inspection reports with CMM data and Cpk covers the content in detail.
What is a first article inspection report?
An FAI report documents that the first parts from a new setup meet every characteristic on the drawing. The requirements come from SAE AS9102C, "Aerospace Series, First Article Inspection Requirements", published 2023-06-28. A standards retailer lists it as the current edition, superseding AS9102B.
The report has three forms. Form 1 is part number accountability and identifies the part and the report. Form 2 is product accountability and records materials, special processes and functional testing. Form 3 is characteristic accountability and lists every characteristic from a ballooned drawing with the measured result next to it. The balloon numbers on the drawing must match the numbers on Form 3.
Secondary summaries of AS9102 list the triggers: the first production run of a new product, a design change, a change of material or source, a change of process, tooling or location, and a lapse in production. The purchase order normally names the trigger. AS9102 is an aerospace standard, so outside aerospace it applies only when the order calls for it. The FAI guide explains how to use the format in other sectors.
What is PPAP, and how does VDA 2 differ?
PPAP, the Production Part Approval Process, is the automotive procedure that shows a supplier's process can make parts that meet all customer requirements at production rate. AIAG publishes it, and the AIAG catalogue lists the 4th edition. Ford's customer-specific requirements, effective 2025-02-06, are written for that edition.
A full package has 18 elements. Those that concern machined parts most directly are design records, the process flow diagram, the process FMEA, the control plan, measurement system analysis, dimensional results, material and performance test results, initial process studies, the sample product, checking aids and the part submission warrant (PSW), which summarises the package and is signed by the supplier. How much of the package goes to the customer depends on the submission level, which the customer sets. AIAG defines five levels.
German OEMs often work to VDA Volume 2 instead, which calls the procedure Production Process and Product Approval (PPA). Its 7th revised edition appeared in January 2026. Its foreword states that scope is now set by the risk level of the product, not by a fixed catalogue of deliverables, and that the 6th edition (2020) removed submission levels. It also notes that harmonisation with AIAG PPAP was discussed but not completed. VDA marks the volume as a non-binding recommendation, so the contract between buyer and supplier decides which procedure applies. Annex 2 of VDA 2 maps its deliverables to the 18 PPAP elements and marks those with no direct equivalent. The PPAP guide for Tier 2 suppliers covers the submission levels.
Which documents should the purchase order name?
Name each document by type, standard and edition, and say who validates it. A line such as "material certificate EN 10204:2004 type 3.1, heat number on each part, CoC with every delivery, FAI report in AS9102C format for the first lot" leaves nothing to interpret. For automotive work, add the PPAP edition or VDA 2 edition and the submission level.
Our network can supply EN 10204 3.1 material certificates, FAI reports, CoCs and measurement reports on request, and the list is fixed per order at quotation. See the quality page for how we work with the audited network in Bursa.
Frequently asked questions
- What is an EN 10204 3.1 certificate?
- An inspection certificate that states the material conforms to the order and gives the results of specific inspection, such as chemical analysis and mechanical tests of the delivered batch. The manufacturer's authorised inspection representative, independent of the manufacturing department, validates it.
- Is a 3.1 certificate the same as a certificate of conformity?
- No. A 3.1 certificate carries test results and is validated by an inspection representative independent of production. A certificate of conformity is the supplier's own declaration that the delivery matches the order, and it contains test values only if the order asks for them.
- Does a 3.1 certificate prove the dimensions of a machined part?
- No. It documents the material, usually as chemistry, strength and a heat or batch number. Dimensions are proved by a measurement report or a first article inspection report.
- What is the difference between FAI and PPAP?
- An FAI report (AS9102 format) documents that one first part meets every drawing characteristic and that materials and special processes are recorded. PPAP is the automotive approval package, with 18 elements, that shows the production process can make conforming parts repeatedly.
- Is AS9102 only for aerospace?
- The standard is an aerospace standard, titled Aerospace Series - First Article Inspection Requirements. A buyer in another sector can still call for an AS9102-format report in the purchase order, and it then applies because the order says so.
Sources
- EN 10204:2004, Metallic products, Types of inspection documents (Irish standards shop, status current)
- EN 10204 certificate types and validation (Wermac, summary of the standard)
- Understanding EN 10204:2004, Type 3.2 Certification (LRQA)
- EN 10168:2004, Steel products, Inspection documents, List of information and description (Irish standards shop, status current)
- ISO/IEC 17050-1:2004, Supplier's declaration of conformity, Part 1 (SFS standards store)
- SAE AS9102C:2023, Aerospace Series, First Article Inspection Requirements (Irish standards shop, supersedes AS9102B)
- AS9102 forms and FAI triggers (InspectionXpert, secondary summary)
- AIAG Quality Core Tools, PPAP manual, 4th edition (AIAG)
- Ford Customer-Specific Requirements for use with AIAG PPAP Fourth Edition, effective 2025-02-06 (IATF Global Oversight)
- VDA Volume 2, Production Process and Product Approval (PPA), 7th revised edition, January 2026 (VDA QMC)
Questions on a drawing? sales@ertas.engineering